Betulin

Betulin at a Glance

Betulin is the reason birch bark is white. It makes up around 22% of the cork tissue of birch outer bark ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}, accumulating as fine crystals that scatter light, and it was one of the first plant compounds ever obtained pure — sublimed out of birch bark in 1788, long before the structure of anything like it was understood.

Its modern significance is unusual for a plant triterpene: it became a licensed medicine. A gel made from birch bark triterpene extract, roughly 80% betulin, is approved in the European Union and the United Kingdom for treating the partial-thickness wounds of epidermolysis bullosa, a rare inherited blistering disease, after a phase III trial that met its primary endpoint ^{2,3Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}. That makes betulin one of very few herbal constituents to complete the whole path from bark to registered drug.

Elsewhere it appears in three unrelated contexts. It is the signature lipophilic marker of the tinder conk (Fomes fomentarius), the bracket fungus of Ötzi’s toolkit, which acquires it from the birch it grows on ^{9,10Reference 9Grienke U et al. · 2014ReviewEuropean medicinal polypores — a modern view on traditional uses — reviewView study →Reference 10Gáper J et al. · 2016ReviewMedicinal value and taxonomy of the tinder polypore, Fomes fomentarius (Agaricomycetes): a review — reviewView study →}. It is the compound in crataeva bark that matched the herb’s marker triterpene lupeol at limiting oxalate crystal damage in rat kidneys ^{6Reference 6Malini MM et al. · 2000AnimalProtective effect of triterpenes on calcium oxalate crystal-induced peroxidative changes in experimental urolithiasis — rat in vivoView study →}. And isolated from paper birch it inhibited herpes simplex virus at sub-microgram concentrations, with synergy against acyclovir ^{5Reference 5Gong Y et al. · 2004In vitroThe synergistic effects of betulin with acyclovir against herpes simplex viruses — in vitroView study →}.

It should not be confused with its oxidation product betulinic acid, which has a different and much more heavily promoted anticancer literature.

From Bark to Registered Drug

Betulin’s clinical story is its most substantial claim, and it comes with an important qualification: the drug is an extract, not the pure molecule.

Oleogel-S10 — marketed as Episalvan and later Filsuvez — is a topical gel of 10% dry birch bark extract in 90% sunflower oil. The extract is a triterpene concentrate in which betulin is the dominant component at roughly 80%, alongside betulinic acid, lupeol, erythrodiol and oleanolic acid ^{1,3Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}. It received central European approval in January 2016 for accelerating closure of partial-thickness wounds, on evidence from an intra-individual comparison design in skin-graft donor sites and burns ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}.

The definitive trial came later. EASE was a double-blind, randomised, vehicle-controlled phase III study in 223 patients with dystrophic, junctional or Kindler epidermolysis bullosa, each with a target partial-thickness wound of 10–50 cm² lasting at least 21 days. Applied at least every four days, the gel produced first complete target wound closure within 45 days in 41.3% of patients versus 28.9% on control gel (relative risk 1.44, 95% CI 1.01–2.05, P = 0.013). Adverse events occurred at the same rate in both arms, and were mostly mild to moderate ^{2Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →}. It is the first therapy to show accelerated wound healing in this disease, and the benefit was maintained through a 24-month open-label extension ^{3Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}.

The proposed mechanism touches all three phases of healing: a temporary stimulation of the inflammatory phase, faster keratinocyte migration toward wound closure, and stimulated epidermal differentiation ^{1,4Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 4Schwieger-Briel A et al. · 2019ReviewMechanism of Oleogel-S10: a triterpene preparation for the treatment of epidermolysis bullosa — reviewView study →}.

Two things are worth keeping straight. The confidence interval on EASE’s primary endpoint runs from 1.01, so the result is real but not large, and it was on a surrogate wound-closure endpoint. And the material tested is a standardised bark extract from European birch — a birch-bark product bought as a supplement is not that, and neither is a different birch species.

Betulin & Betulinic Acid

The two molecules are one oxidation apart and are constantly conflated. Betulin is a diol, with hydroxyl groups at C-3 and C-28; betulinic acid has that C-28 position oxidised to a carboxylic acid. Betulin is the biosynthetic precursor and the industrial starting material, since converting bark-derived betulin is the cheapest route to betulinic acid.

Their reputations diverge sharply. Betulinic acid carries a large anticancer literature and gave rise to derivatives explored as HIV maturation inhibitors. Betulin’s own profile is the wound-healing programme above, the lipid and antiviral findings below, and its role as the raw material.

Because the clinical extract contains both, together with lupeol, an effect attributed to “birch triterpenes” cannot be assigned to either molecule alone ^{3,4Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →Reference 4Schwieger-Briel A et al. · 2019ReviewMechanism of Oleogel-S10: a triterpene preparation for the treatment of epidermolysis bullosa — reviewView study →}. The extract’s own composition is the reason to keep them apart.

What It's Used For

Betulin has one licensed topical use and a scattered preclinical literature in which the recurring limitation is the same: it is a large, waxy, essentially water-insoluble triterpene, so oral work needs formulation tricks and the concentrations used in cells are not reached by eating anything.

A licensed wound treatment, as an extract:the birch triterpene gel met its primary endpoint in phase III for epidermolysis bullosa, 41.3% versus 28.9% wound closure at 45 days, and is approved in the EU and UK ^{2,3Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}.

A defined healing mechanism:transient stimulation of the inflammatory phase, accelerated keratinocyte migration, and stimulated epidermal differentiation ^{1,4Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 4Schwieger-Briel A et al. · 2019ReviewMechanism of Oleogel-S10: a triterpene preparation for the treatment of epidermolysis bullosa — reviewView study →}.

Antiviral, and species-matched:betulin isolated from Betula papyrifera bark inhibited HSV-1 at an EC₅₀ of 0.40 µg/mL (HSV-2 4.15) against a CC₅₀ of 73.1, with strong synergy with acyclovir above 0.4 µg/mL ^{5Reference 5Gong Y et al. · 2004In vitroThe synergistic effects of betulin with acyclovir against herpes simplex viruses — in vitroView study →}.

A specific metabolic target:betulin inhibits SREBP, the master transcriptional regulator of cholesterol and fatty-acid synthesis, improving hyperlipidaemia and insulin resistance and reducing atherosclerotic plaque in mice ^{7Reference 7Tang JJ et al. · 2011AnimalInhibition of SREBP by a small molecule, betulin, improves hyperlipidemia and insulin resistance and reduces atherosclerotic plaques — mouse in vivoView study →}; a second study attributes plaque reduction to raised ABCA1 and ABCG1 ^{8Reference 8Gui YZ et al. · 2016AnimalBetulin attenuates atherosclerosis in apoE(-/-) mice by up-regulating ABCA1 and ABCG1 — mouse in vivoView study →}.

The honest limit:apart from the topical extract, everything is animal or cell work, the oral bioavailability problem is unsolved, and the wound-healing evidence belongs to a European birch bark extract, not to birch bark generally.

Evidence by IndicationStrength of support · Beta

The application that made betulin a medicine. Birch bark triterpene dry extract (about 80% betulin), formulated as a 10% gel in sunflower oil, was first approved in central Europe in January 2016 for accelerating closure of partial-thickness wounds, on the strength of intra-individual comparison studies in skin-graft donor sites and burn wounds ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}.

The EASE phase III trial then tested it in the harder setting: 223 patients with dystrophic, junctional or Kindler epidermolysis bullosa and a persistent target wound of 10–50 cm². First complete closure within 45 days was reached by 41.3% on the gel against 28.9% on vehicle (RR 1.44, 95% CI 1.01–2.05, P = 0.013), with adverse events at the same rate in both arms ^{2Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →}.

Benefits on wound burden were maintained over a 24-month open-label extension, and the product is approved in the EU and UK for patients from six months of age ^{3Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}.

Mechanistically the preparation acts across all three healing phases — a temporary boost to inflammation, then faster keratinocyte migration, then stimulated epidermal differentiation ^{1,4Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 4Schwieger-Briel A et al. · 2019ReviewMechanism of Oleogel-S10: a triterpene preparation for the treatment of epidermolysis bullosa — reviewView study →}.

Gap: the trial tested a standardised extract containing several triterpenes, so the effect cannot be assigned to betulin alone; the endpoint is wound closure rather than a patient-reported outcome; and the confidence interval’s lower bound sits at 1.01.

Mechanisms

Target / pathway	Effect	Relevant to
Keratinocyte migration and differentiation	Faster migration to wound closure; stimulated epidermal differentiation after a transient inflammatory phase	The licensed wound indication
Herpes simplex replication	EC₅₀ 0.40 µg/mL (HSV-1); synergy with acyclovir	Antiviral
SREBP / SCAP maturation	Inhibited → lower cholesterol and fatty-acid synthesis	Metabolic (mouse)
ABCA1 / ABCG1	Up-regulated → cholesterol efflux, less plaque	Atherosclerosis (mouse)
Calcium oxalate crystal aggregation; SOD, catalase, GPx	Inhibition and restoration respectively	Renal protection (rat)
Conversion to betulinic acid	Oxidation at C-28 — the industrial route and a metabolic possibility	Why the two literatures blur

The topical row is the only one supported in people; the rest are targets in animals, held back by the same physical problem — a waxy, water-insoluble triterpene is hard to get anywhere except the skin.

Pharmacokinetics

Betulin’s pharmacokinetics is mostly a description of an obstacle. It is a large pentacyclic triterpene with two hydroxyl groups and essentially no water solubility, so oral absorption is poor and much of the published work on delivering it involves nanoparticles, lipid conjugates and other formulation strategies rather than plain dosing. That is the reason its clinical development went topical: dispersed in sunflower oil and applied to a wound, none of the absorption problem applies, and the gel is designed to act locally on the wound bed rather than systemically ^{1,4Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 4Schwieger-Briel A et al. · 2019ReviewMechanism of Oleogel-S10: a triterpene preparation for the treatment of epidermolysis bullosa — reviewView study →}. Systemic exposure from the licensed gel has not been characterised in the sources examined, and no human oral pharmacokinetic study of betulin was found. In the body it can be oxidised at C-28 toward betulinic acid, which complicates attributing effects between the two.

Clinical Trials

Human evidence is confined to the topical birch triterpene extract: intra-individual comparison studies in graft donor sites and burns ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}, and the EASE phase III trial in epidermolysis bullosa with its 24-month extension ^{2,3Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}. No trial has given isolated betulin to people by any route.

Completed	Planned	Terminated	Preclinical
EASE phase III (n = 223) + 24-month extension; earlier wound-closure studies — all the extract	—	—	Antiviral, SREBP/metabolic, renal (cell and rodent)

Last checked: September 2026.

Isolate vs. Plant Studies

Betulin inverts the usual pattern in a specific way. The human evidence is neither isolate nor whole plant but a standardised fraction — a triterpene dry extract of birch bark, about 80% betulin, with betulinic acid, lupeol, erythrodiol and oleanolic acid making up the rest ^{1,3Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}. That is stronger than a crude extract, because the composition is defined and reproducible, and weaker than an isolate, because the trial cannot say which triterpene did the work.

The isolate evidence is preclinical: the HSV plaque-reduction assay used betulin purified from paper birch bark ^{5Reference 5Gong Y et al. · 2004In vitroThe synergistic effects of betulin with acyclovir against herpes simplex viruses — in vitroView study →}, the SREBP work used the pure compound in mice ^{7Reference 7Tang JJ et al. · 2011AnimalInhibition of SREBP by a small molecule, betulin, improves hyperlipidemia and insulin resistance and reduces atherosclerotic plaques — mouse in vivoView study →}, and the crataeva result compared purified betulin against purified lupeol ^{6Reference 6Malini MM et al. · 2000AnimalProtective effect of triterpenes on calcium oxalate crystal-induced peroxidative changes in experimental urolithiasis — rat in vivoView study →}.

Two transfer failures are worth naming. Species: the clinical programme, and the European pharmacopoeial birch monographs, belong to Betula pendula and B. pubescens. Paper birch (Betula papyrifera) shares the molecule but not the evidence — although it is the species in which the antiviral result was obtained, which makes that finding the species-matched one. Preparation: chewing bark, brewing bark tea or buying a birch supplement does not reproduce a triterpene concentrate in an oleogel, and betulin’s insolubility means a water extract carries very little of it.

Its Role in Plants and Fungi

In birch, betulin is a bark defence and structural compound. It accumulates in the cork tissue of the outer bark as microscopic crystals, and it is those crystals — not a pigment — that make the bark white and reflective. The waxy, hydrophobic layer they form waterproofs the bark, and the triterpene fraction as a whole resists microbial and fungal attack, which is part of why birch bark survives so long in the ground that Neolithic birch-bark tar has been recovered intact.

Its appearance in the tinder conk (Fomes fomentarius) is second-hand. The fungus is a birch parasite and saprotroph, and betulin is described as its signature lipophilic marker — a compound it takes up from its host rather than makes ^{9,10Reference 9Grienke U et al. · 2014ReviewEuropean medicinal polypores — a modern view on traditional uses — reviewView study →Reference 10Gáper J et al. · 2016ReviewMedicinal value and taxonomy of the tinder polypore, Fomes fomentarius (Agaricomycetes): a review — reviewView study →}. That distinction matters for anyone reading a mushroom’s constituent list: a marker acquired from the substrate is a fingerprint of what the fungus grew on.

Prevalence in Nature

Birch outer bark is the dominant source by a wide margin, at about 22% betulin in the cork tissue ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}. The scale is what makes the drug possible: Northern Europe’s wood-processing industry generates birch bark as a by-product on the order of hundreds of thousands of tonnes a year, so the active ingredient is available in bulk without harvesting anything for the purpose ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}.

Beyond birch it is a minor to moderate constituent of a scattered set of barks and plants. It is one of the pentacyclic triterpenes of crataeva stem bark alongside lupeol, betulinic acid and lupeol acetate ^{6Reference 6Malini MM et al. · 2000AnimalProtective effect of triterpenes on calcium oxalate crystal-induced peroxidative changes in experimental urolithiasis — rat in vivoView study →}, and it appears in the triterpene fractions of shrubby bushclover, zizyphus, bael and bacopa. In fungi, tinder conk carries it as a birch-derived marker ^{9,10Reference 9Grienke U et al. · 2014ReviewEuropean medicinal polypores — a modern view on traditional uses — reviewView study →Reference 10Gáper J et al. · 2016ReviewMedicinal value and taxonomy of the tinder polypore, Fomes fomentarius (Agaricomycetes): a review — reviewView study →}.

Discovery & Synthesis

Betulin has a claim to being one of the first pure plant natural products ever isolated. In 1788 Tobias Lowitz obtained it from birch bark by sublimation — the compound crystallises straight out of heated bark — decades before most plant chemistry was possible at all, and it takes its name from Betula.

There is no meaningful total synthesis, because there is no need for one: birch bark is up to a fifth betulin by weight, and extraction from wood-industry bark waste supplies both the compound itself and the feedstock for making betulinic acid and other semi-synthetic derivatives ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}. The pharmaceutical process makes a triterpene dry extract rather than pure betulin, since the extract is what the licensed product uses ^{1,3Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}.

Toxicity & Safety

Betulin carries a low flag. In the phase III trial, adverse events occurred at essentially the same rate on the birch triterpene gel as on vehicle gel — 81.7% against 80.7%, mostly mild to moderate, with 4.6% severe — in a population of patients with fragile, chronically wounded skin, which is a demanding test of a topical product ^{2Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →}. Tolerability was similar to control through 24 months of continued use ^{3Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}.

Its poor oral absorption limits systemic exposure from anything eaten, and no isolate toxicology of concern was located. Two honest caveats: no comprehensive isolate toxicology package (genotoxicity, repeat-dose, reproductive) exists, so confidence rests on the clinical tolerability of the extract and on low absorption rather than on a full dossier; and birch bark preparations are not betulin. Birch bark and related species carry other constituents that are not benign — paper birch’s papyriferic acid, for instance, is a mitochondrial succinate-dehydrogenase inhibitor and the tree’s antifeedant — so a concentrated home-made bark preparation cannot be assumed safe on betulin’s record. Pregnancy and lactation decisions for a birch product belong on the herb or product page.

Safety at a Glance

Low / no toxicity

Well tolerated in its licensed use. Adverse events 81.7% on gel versus 80.7% on vehicle in fragile-skinned patients, sustained over 24 months.
Poorly absorbed orally, which limits systemic exposure from bark preparations.
The evidence is for a standardised European birch bark extract, not for bark, tea, or a supplement, and not for other birch species.
Birch bark contains more than betulin. Paper birch’s papyriferic acid is a mitochondrial toxin; a concentrated bark preparation is not covered by betulin’s safety record.
No full isolate toxicology dossier was located; safety rests on clinical tolerability of the extract and low absorption.

Dosage

There is no oral dose of betulin. Its human use is the licensed topical gel; the other figures are research doses and concentrations. These are doses studied in research and are not a personal recommendation.

Context	Form	Dose / concentration
Epidermolysis bullosa, partial-thickness wounds	Gel of 10% dry birch bark extract (~80% betulin) in 90% sunflower oil	Applied to wounds at least every 4 days ^{2,3Reference 2Kern JS et al. · 2023RCTEfficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trialView study →Reference 3Heo YA · 2023ReviewBirch bark extract: a review in epidermolysis bullosa — reviewView study →}
Wound closure (graft donor sites, burns)	Same preparation	Topical, to wound closure ^{1Reference 1Scheffler A · 2019ReviewThe wound healing properties of betulin from birch bark from bench to bedside — reviewView study →}
Antiviral (in vitro)	Purified betulin	EC₅₀ 0.40 µg/mL HSV-1; CC₅₀ 73.1 µg/mL ^{5Reference 5Gong Y et al. · 2004In vitroThe synergistic effects of betulin with acyclovir against herpes simplex viruses — in vitroView study →}
Metabolic and renal models	Purified betulin, formulated	Mouse and rat research dosing ^{6,7,8Reference 6Malini MM et al. · 2000AnimalProtective effect of triterpenes on calcium oxalate crystal-induced peroxidative changes in experimental urolithiasis — rat in vivoView study →Reference 7Tang JJ et al. · 2011AnimalInhibition of SREBP by a small molecule, betulin, improves hyperlipidemia and insulin resistance and reduces atherosclerotic plaques — mouse in vivoView study →Reference 8Gui YZ et al. · 2016AnimalBetulin attenuates atherosclerosis in apoE(-/-) mice by up-regulating ABCA1 and ABCG1 — mouse in vivoView study →}

References

Scheffler A (2019). The wound healing properties of betulin from birch bark from bench to bedside — review. Planta Med. https://pubmed.ncbi.nlm.nih.gov/30856673/
Kern JS, Sprecher E, Fernandez MF, et al. (2023). Efficacy and safety of Oleogel-S10 (birch triterpenes) for epidermolysis bullosa: results from the phase III randomized double-blind phase of the EASE study — randomised controlled trial. Br J Dermatol. https://pubmed.ncbi.nlm.nih.gov/36689495/
Heo YA (2023). Birch bark extract: a review in epidermolysis bullosa — review. Drugs. https://pubmed.ncbi.nlm.nih.gov/37658982/
Schwieger-Briel A, Ott H, Kiritsi D, et al. (2019). Mechanism of Oleogel-S10: a triterpene preparation for the treatment of epidermolysis bullosa — review. Dermatol Ther. https://pubmed.ncbi.nlm.nih.gov/31168940/
Gong Y, Raj KM, Luscombe CA, et al. (2004). The synergistic effects of betulin with acyclovir against herpes simplex viruses — in vitro. Antiviral Res. https://pubmed.ncbi.nlm.nih.gov/15498608/
Malini MM, Lenin M, Varalakshmi P (2000). Protective effect of triterpenes on calcium oxalate crystal-induced peroxidative changes in experimental urolithiasis — rat in vivo. Pharmacol Res. https://pubmed.ncbi.nlm.nih.gov/10704264/
Tang JJ, Li JG, Qi W, et al. (2011). Inhibition of SREBP by a small molecule, betulin, improves hyperlipidemia and insulin resistance and reduces atherosclerotic plaques — mouse in vivo. Cell Metab. https://pubmed.ncbi.nlm.nih.gov/21195348/
Gui YZ, Yan H, Gao F, et al. (2016). Betulin attenuates atherosclerosis in apoE(-/-) mice by up-regulating ABCA1 and ABCG1 — mouse in vivo. Acta Pharmacol Sin. https://pubmed.ncbi.nlm.nih.gov/27374487/
Grienke U, Zöll M, Peintner U, et al. (2014). European medicinal polypores — a modern view on traditional uses — review. J Ethnopharmacol. https://pubmed.ncbi.nlm.nih.gov/24786572/
Gáper J, Gáperová S, Pristas P, et al. (2016). Medicinal value and taxonomy of the tinder polypore, Fomes fomentarius (Agaricomycetes): a review — review. Int J Med Mushrooms. https://pubmed.ncbi.nlm.nih.gov/27910753/